N-Tune Humbucker style OnBoard Chromatic Guitar and Bass Tuner No drilling or permanent modifiction required Accuracy Built right into your guitar or bass: +/- 2 cents True bypass design preserves your instrument's original tone Includes Black,White,Fender -Cream,Gibson -Cream and Parchment colored tuning rings For use in most electric guitars and basses with Humbucker style pickups using a 500k ohm volume pot